Self-squaring curtain stretcher



Nov. 7, 1939. J. J. DVORAK $ELF-SQUARING CURTAIN STRETCHER Filed April 6, 1937 I Patented Nov. 7, 1939 UNi'lED STATES PATENT OFFlCE 4 Claims.

The conventional type of curtain stretcher comprises a plurality of superimposed members fastened at their ends by wing nuts and bolts which pass through longitudinal slots in the superimposed members. These stretchers possess a number of disadvantages, chief among which is that the free ends of the attaching pins lie in spaced planes, thereby causing the stretched curtain to wrinkle along its edges and also making it difficult to attach a curtain to the stretcher, particularly in the case of curtains of heavier material. Furthermore, in these conventional stretchers the superimposed members have a tendency to pivot about the joining bolt and thereby cause the stretcher to assume shapes other than-rectangular. This results in the improper stretching of the curtain by warping it out of the proper shape and such curtains when placed in position do not hang vertically.

It is accordingly an object of applicants invention to provide a curtain stretcher free of such defects wherein the detachable members or bars comprising the assembled stretcher automatically assume on assembly a perpendicular relation to each other and wherein said detachable members and the attaching pins embedded in the several members lie in common planes.

A further object of the invention is to provide clamping members which are readily manipulatable to assemble the several stretcher bars, said clamping members causing the stretcher bars to automatically assume a perpendicular relation to each other.

Another object of the invention is to provide a clamp which shall be adapted to be fixedly secured to each bar of a curtain stretcher and adapted to detachably receive and clamp another bar at right angles to the first bar; which shall be adapted to clamp the associated bars to a supporting standard or brace and which shall provide means for engaging said brace at spaced points whereby to more effectively support the joined stretcher upon said standard or brace.

Another object of applicants invention is to provide a curtain stretcher which can be readily assembled and adjusted to form a substantially rigid structure capable of accommodating all sizes of curtains.

Other and, further objects and advantages of 1e invention will be apparent from the following description when taken in connection with the accompanying drawing wherein:

Fig. l is a perspective View of the construction embodying applicants invention.

Fig. 2 is a fragmentary vertical section taken on the line 22 of Fig. 1.

Fig. 3 is a fragmentary horizontal section taken on the line 3-3 of Fig. 1. r

Fig. 4is a fragmentary Vertical section taken along the line 4-4 of Fig. 1.

Fig. 5 is a fragmentary vertical section taken on the line 5-5 of Fig. 1.

Fig. 6 is an exploded view in perspective of the clamping and supporting member.

As shown in the drawing the curtain stretcher is adapted to be assembled upon and supported by a pair of standards or braces 2. Each of the standards comprises a forward leg 3 and a rear supporting leg i collapsibly connected to the forward leg by the usual sheet metal pivot fitting 6. Each of the forward legs 3 is provided with a longitudinal slot 8 of substantial length and an aperture IE1 adjacent its upper end. A set of four stretcher members or bars I2 is provided and each of these bars is provided with a tapering portion M of reduced cross section through which extends the usual attaching pins it for receiving and securing the curtain to the assembled stretcher. A clamping and supporting member It is secured to one end of each of the four bars l2. Each of these clamping members comprises a stamping having a main body 20, an intermediate offset portion 2'2, a clamping portion 23, a forwardly bent end portion 24 and an opposite end portion 26 oiiset from the main body portion 29 the same amount as the offset portion 22. The main body portion 20 is apertured as at 28 and Silto receive rivets or bolts 32 and 34 for fixedly securing the clamping member to a stretcher bar. The intermediate offset portion 22 is provided with a square aperture 36 adapted to receive the similarly shaped portion of an attaching bolt 31 with which a wing nut 38 is associated to secure the stretcher bar to the forward leg 3 of the supporting stand. The end portion 24 is bent at right angles to the main body por tion and is provided With a threaded boss 39 to receive a thumb screw Ml. An adjustable clamping plate 42 is secured to the reduced end portion 44 of the thumb screw ill, the portion 44 extending through a countersunk aperture 46 in the clamping plate and being upset in said countersunk portion in a manner to secure the plate against longitudinal movement relative to the thumb screw but to permit relative rotation therebetween. The clamping plate 42 is provided at its outer end with an upturned flange portion 48 and at its inner end with a downwardly extending central portion forming a lug 50 and a pair of spaced ears or lugs 52 and 5 5. The lugs 5d, 332 and 54 provide means for guiding the clamping plate 42 and for maintaining said plate at right angles to the main body portion of the clamping member. The flange 18 provides for retaining the stretcher bar l2 against movement outwardly of the clamping member. The offset end portion 25 in cooperation with the offset portion 22 provides means for engaging the forward leg 2 of the supporting standard at spaced points to increase the rigidity of the assembled structure. provided with strengthening ribs or webs and 58.

It will be apparent from Fig. 2 that the clamping member it causes the assembled stretcher bars to lie in a common plane and automatically to assume a perpendicular relation to each other.

Extension members or bars 60 are provided for increasing the length of the stretcher. Each of these extension bars is similar in construction to the stretcher bars i2 and is provided at one end with a generally U-shaped sheet metal stamping or fish plate 52 riveted thereto and extending therefrom to receive the free end of one of the bars l2. The plate 62 is adapted to be secured to the bar it by a bolt 83 passing through suitable apertures in the bar and plate, a wing nut (not shown) cooperating with the bolt 64 for this purpose. One leg of the U-shaped plate 62 is of less height than the other to correspond with the thickness of the edge of the tapering portion IA of the bar l2 and extension bar 68. When a bar fill is fastened to a bar l2 in the manner stated, it forms with the bar l2 that which is in effect a single stretcher bar of variable length.

When the extension members 60 are used to increase the length of the stretcher there is a tendency for the assembled horizontal bars to sag and for this reason an additional brace or supporting leg i5 is provided. This brace 56 may be identical in construction with the forward leg 3 of the supporting standard and is similarly provided with a longitudinal slot 8'! and an aperture (not shown) adjacent its upper end, the attaching bolts 55 associated with the upper bars l2 and 59 passing through this last mentioned aperture and securing said bars to the brace 66. Support for the lower bar i2 is offered by a spring steel fitting 68 adjustably secured to the brace (it by a bolt in and wing nut 12, the bolt 1!] passing through the slot 6'? in the brace 66. The spring steel fitting 68 is generally J-shaped in cross section, suitable apertures being provided in the spaced legs i l and '18 to receive the shank and squared end of the bolt ill. The forward leg 76 of the fitting 68 is provided with a forwardly and upwardly bent portion '58 forming a seat and a retaining flange for receiving the stretcher bar l2, and the upper end of the rear leg M is bent forwardly to provide a flange 8i adapted to cooperate with the portion '53 in maintaining the bar 52 and brace 66 at right angles to each other.

The bars 82 and 6% having been secured together by the bolts 3, the several stretcher members may be assembled in any desired order by manipulating the thumb screw til associated with the clamping members l8 carried by the bars H2. The assembled stretcher may be mounted upon the standards 2 by inserting the bolts 3? associated with the clamping members 58 into the apertures it! and slots 3 in the forward legs 3 of said standards. The bar E2 of the lower set of bars I2 and 63 is connected to the brace 65 by placing said bar in the seat formed by the flange The clamping member i8 is additionally" 8t and bent portion E8 of the fitting l8 and upon manipulation of the wing bolt '52, the legs M and E5 of said fitting will be drawn together frictionally to clamp the bar against movement relative to the brace.

If desired the several stretcher members may be assembled dir ctly upon the standards by first inserting the bolt 3'5 associated with the upper bar iii in the upper aperture It of one standard and by inserting the similar bolt 3'! associated with one end member H2 in the corresponding upper aperture iii in the other standard.

The stretcher herein disclosed is capable of ready adjustment to accommodate different sizes of curtains. Adjustment to increase or decrease the length or width of the stretcher can be accomplished by merely loosening the diagonally opposits thumb screws ii and the wing nut 12. If it is desired to vary the length of the stretcher, the vertical bars 52, or the standards 2, may then be pulled apart or moved together. If it is desired to vary the Width, the proper thumb screws 3G and wing nut '82 having been loosened, it is merely necessary to move up or down the lower pair of joined bars l2 and 5E E /"here curtains of a length less than the bars 52 are to be stretched, the bars GEl'and brace 66 need not be employed, the free ends of the horizontal bars it being clamped directly to the vertical bars 52.

Chan es may be made in the form, construction and arrangement of the parts without departing from the spirit of the invention or sacrificing any of its attendant advantages, and the rigll. v is reserved to make all such changes as fairly fall within the scope of the following claims.

he invention is hereby claimed as follows:

1. A curtain stretcher comprising a plurality of stretcher bars, a pair of supporting standards, a plurality of clamping devices for clamping adjacent bars and securing the same to said standards, said clamping devices each comprising a clamping member having a main body portion fixedly secured to a stretcher bar, a clamping portion lying in the same plane as said body portion and adapted to extend beyond the end edge of said bar, said clamping portion having an outwardly oiiset section, and an end portion bent at right angles to the plane of said clamping and body portions, means carried by said offset section for securing the bar to a standard, adjustable clamping means slidably mounted upon the clamping port-ion of said clamping member and extending at right angles thereto to receive and position the adjacent bar and means carried by the end portion of said clamping member for adjusting said adjustable means whereby to clamp adjacent bars together and to cause said bars automatically to assume a perpendicular relation to each other.

2. A curtain stretcher comprising a plurality of stretcher bars, a pair of supporting standards, a pluralityof clamping devices for clamping adjacent bars and securing the same to said standards, said clamping devices each comprising a member formed to provide a main body portion fixedly secured to one face of a stretcher bar, a clamping portion lyin in the same plane as said body portion extending beyond the end edge of said bar, said clamping portion having an ofiset section, and an end portion bent at right angles to the plane of said body and clamping portions, means carried by said offset section for securing the bar to a standard, an adjustable clamping plate having a base portion, a plurality of spaced guiding lugs extending outwardly in the plane of the clamping plate to engage the side edges of the clamping portion of the fixed member and a laterally directed flange engaging the face of said clamping portion for maintaining said plate parallel to the end portion of said clamping member and means carried by said end portion for adjusting said clamping plate Whereby adjacent bars are clamped together and automatically assume a perpendicular relation, said clamping plate having a retaining flange extending from the outer end of said base portion and adapted to cooperate with the clamping portion of the fixed clamping member to retain the joined bars in a common plane.

3. A curtain stretcher comprising a plurality of stretcher bars, a pair of supporting standards, a plurality of clamping devices for clamping adjacent bars and securing the same to said standards, said clamping devices each comprising a member formed to provide a main body portion fixedly secured to one face of a stretcher bar, a

clamping portion lying in the same plane as said body portion and extending beyond the end edge of said bar, said body portion and said clamping portion having offset sections forming supporting feet to engage said standard at spaced points, and an end portion bent at right angles to the plane of said body and clamping portions, means carried by one of said offset portions for securing the bar to a standard, an adjustable clamping plate having a base portion for maintaining said plate parallel to the end portion of said clamping member and means carried by said end portion for adjusting said clamping plate whereby adjacent bars are clamped together and automatically assome a perpendicular relation.

4. A device for detachably joining a pair of bars of a curtain stretcher, comprising a clamping member formed to provide a body portion adapted to be fixedly secured to one face of one of said bars, a clamping portion lying in the same plane as said body portion and adapted to extend beyond the end edge of said one bar, and an end portion 'bent at right angles to the plane of said body and clamping portions, an adjustable clamping plate having a base portion adapted to engage the outer side of the other of said pair of bars, said clamping plate having a retaining flange directed laterally from the outer edge of said base portion and adapted to extend over the outer face of said bar and said plate further having a guiding flange directed laterally from the inner edge of said base portion and oppositely to said retaining flange, and means carried by said end portion for adjusting said clamping plate, whereby said other bar is clamped to said one bar and automatically assumes a perpendicular relation thereto, the retaining flange of the clamping plate cooperating with the clamping portion of the fixed clamping member to retain the joined bars in assembled relation and the guiding flange enaging the clamping portion of the clamping member outwardly of the bars to maintain the bars in perpendicular relation.

' JAMES J. DVORAK. 

